Method and apparatus for assessing or detecting brain injury and neurological disorders

ABSTRACT

A method and apparatus is provided for diagnosing, assessing, or detecting brain injury and/or a neurological disorder of a subject. Objects are presented to the subject over a range of locations within the subject&#39;s workspace such that the subject can interact with at least some of the presented objects using either the right or left limb, or portion thereof, of a pair of limbs. Position data and/or motion data and/or kinetic data of the left and right limbs or portions thereof with respect to a presented object are obtained, and a data set is acquired for a plurality of presented objects. The acquired data set provides information about brain injury and/or a neurological disorder in the subject.

RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S.Provisional Application No. 61/405,504, filed on 21 Oct. 2010, thecontents of which are incorporated herein by reference in theirentirety.

FIELD

This invention provides methods and apparatus for detecting andassessing brain injuries and/or neurological disorders in subjects. Inparticular, brain injuries and/or neurological disorders that involveimpaired sensory, motor, and cognitive processes may be detected andassessed.

BACKGROUND

Movement and interaction within the environment requires a subject tosense the environment using visual, audio, and other sensory processes,as well as sense her/his body position and movement. The sensory,cognitive, and motor processes required are normally performed withspeed and accuracy. However, when an individual suffers a brain injuryfrom trauma, stroke, or the like, there can be a broad range of sensory,motor, and/or cognitive functions that are impaired (Teasell et al.,2003), reducing the individual's ability to move and interact within theenvironment. This leads to a substantive impact on the individuals'ability to perform daily activities.

Clinical assessment plays a crucial role in all facets of patient care,from diagnosing a specific disease or injury, to management andmonitoring of therapeutic or rehabilitation strategies to amelioratedysfunction (Van Dursen and Brent, 1997). Medicine relies on a breadthof technologies and tests to quantify the function of various organsystems that has radically changed the process of diagnosing disease.However, the ability to assess the function of the brain, particularlysensory, motor, and cognitive functions, is surprisingly limited andcontinues to be based largely on subjective estimates of performance.For example, assessing the ability of a patient to touch their nose anda clinician's finger repeatedly based on a score of 0, 1, or 2. Suchsubjective rating systems are necessarily coarse to ensure reliabilityand validity, but such coarseness makes it difficult to detect subtlechanges in sensorimotor function. Furthermore, subtle impairments suchas small delays in reacting or increases in movement variability cannotbe identified easily from visual inspection. Evidence-based reviews ofstroke rehabilitation recommend sensorimotor assessments based onordinal scales. The most reliable of such scales have relatively coarserating systems, reflecting that it is difficult for even an experiencedobserver to discriminate small changes in performance using only thenaked eye.

A number of pen and paper tasks have been developed to quantifycognitive processes. However, such tasks often do not consider the speedof a subject's ability to complete a task and therefore may be limitedin their effectiveness as a tool to assess cognitive processes essentialfor everyday activites.

Automated processes have been developed such as computer basedassessments. For example, CANTAB provides a range of specialized tasksto assess various aspects of cognitive function by having subjects useone of their limbs to contact and interact with a computer screen.Devices such as Dynavision may be used to quantify how subjects respondto stimuli across a large portion of the workspace by recording thereaction time for the subject to hit various targets that areilluminated at random times. Various technologies have also beendeveloped to quantify limb movement, such as robots that can quantifythe ability of subjects to make visually guided reaching movements(e.g., KINARM, U.S. Pat. No. 6,155,993 issued 5 Dec. 2000 to Scott).

While such technologies provide a range of information on sensorimotorperformance, they lack the ability to assess several key aspects ofnormal sensorimotor and cognitive function that are crucial forperforming daily activities. For example, the decision to reach for anobject requires one to decide which limb to use. In many cases, theselection is based on the proximity of the object, the ongoing action ofeach limb along with general preferences for using one limb over theother for certain tasks (hand preference). Brain injuries are oftenasymmetric with greater impairments in sensory or motor functions forone side of the body as compared to the other. This may affect how anindividual with a brain injury chooses one limb versus the other toperform a task.

A further effect of brain injury may be the subject's inability torespond to or interact with parts of her/his workspace. For example, asubject with a lesion involving the right parietal cortex may havedifficulty responding to objects in the left part of the workspace.Traditional pen and paper tasks such as the Behavioural Inattention Test(BIT) may be used to quantify this deficit. However, because a timelimit is usually not imposed on subjects performing this task and only asmall region of the workspace sampled (i.e., the size of paper used),the test is of limited ability to quantify impairments in this domain.

SUMMARY

One embodiment described herein provides method for diagnosing,assessing, or detecting brain injury and/or a neurological disorder of asubject, comprising: presenting objects to the subject within thesubject's workspace such that the subject can interact with thepresented objects using either the right or left limb, or portionthereof, of a pair of limbs; using data acquisition apparatus to obtainposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object;constructing a data set from the obtained data for a plurality ofpresented objects; and analyzing the data set and outputting a resultthat provides information about condition of the brain and/orneurological status in the subject; wherein presenting objects includespresenting objects to the subject within the subject's workspace suchthat two or more objects are in the subject's workspace simultaneously;or wherein a next object is presented to the subject before the subjectcan move the right or left limb, or portion thereof, to a selectedposition after interacting with a previous object.

Also described herein is a method for diagnosing, assessing, and/ordetecting brain injury and/or a neurological disorder of a subject,comprising: presenting objects to the subject over a range of locationswithin the subject's workspace such that the subject can interact withat least some of the presented objects using either the right or leftlimb, or portion thereof, of a pair of limbs; obtaining position dataand/or motion data and/or kinetic data of the left and right limbs orportions thereof with respect to a presented object; acquiring a dataset by repeating the obtaining for a plurality of presented objects;wherein the acquired data set provides information about brain injuryand/or a neurological disorder in the subject.

Also described herein is a method for diagnosing, assessing, ordetecting brain injury and/or a neurological disorder of a subject,comprising: presenting objects to the subject over a range of locationswithin the subject's workspace such that the subject can interact withat least some of the presented objects using either the right or leftlimb, or portion thereof, of a pair of limbs; using data acquisitionapparatus to obtain position data and/or motion data and/or kinetic dataof the left and right limbs or portions thereof with respect to apresented object; acquiring a data set by obtaining position data and/ormotion data and/or kinetic data of the left and right limbs or portionsthereof for a plurality of presented objects; and analyzing the data setand outputting a result; wherein the result provides information aboutbrain injury and/or a neurological disorder in the subject.

In the methods described herein, the data acquisition apparatus maycomprise a mechanical linkage, or wired or wireless sensors adapted tobe attached to left and right limbs of a pair of limbs of a subject, andmeans that detects output signals from the one or more sensors, or oneor more cameras, or a combination thereof, to obtain position dataand/or motion data and/or kinetic data of the left and right limbs orportions thereof with respect to a presented object.

The methods may comprise determining from the position data and/ormotion data and/or kinetic data whether the left limb or right limb wasused with respect to a presented object; and repeating the determiningfor a plurality of presented objects to produce the acquired data set.Determining may include relating location of a presented object withinthe subject's workspace to the location of the left limb or right limbthat was used to interact with the presented object; and repeating therelating for a plurality of presented objects to produce the acquireddata set.

The methods may comprise recording one or more autonomic functions ofthe subject with respect to a presented object; and repeating therecording for a plurality of presented objects; wherein data for the oneor more autonomic functions together with the acquired data set provideinformation about brain injury and/or neurological disorder in thesubject. The one or more autonomic functions may be selected from heartrate and blood pressure.

The methods may comprise presenting the objects to the subject usingvirtual reality or augmented reality; whereby the virtual reality oraugmented reality is two-dimensional or three-dimensional.

The methods may comprise using a mechanical linkage to obtain positiondata and/or motion data and/or kinetic data of the left and right limbsor portions thereof with respect to presented objects; wherein thesubject's left and right limbs or portions thereof are in contact withthe mechanical linkage. The subject may hold on to the mechanicallinkage with the left and right limbs or portions thereof. The left andright limbs or portions thereof may be attached to the mechanicallinkage.

The methods may comprise using a motion tracking system to obtainposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object.

The methods may comprise determining kinetic trajectory data of a limbwith respect to a presented object; wherein kinetic trajectory dataprovides information about brain injury and/or a neurological disorderin the subject.

The method may comprise determining speed and/or velocity of a limb withrespect to a presented object; wherein the speed and/or velocity dataprovides information about brain injury and/or a neurological disorderin the subject.

The presented objects may include at least one characteristic selectedfrom: (i)

presented objects are stationary; (ii) presented objects are moving;(iii) presented objects are moving at different speeds; (iv) fixednumber of presented objects at any given time; (v) variable number ofpresented objects at any given time; (vi) presented objects have thesame characteristics; (vii) presented objects have differentcharacteristics; (viii) duration of visibility of each presented objectis the same; (ix) duration of visibility of each presented object isdifferent; wherein data indicating an effect or no effect of acharacteristic of a presented objects on the subject's behaviour withrespect to a presented object provide information about brain injuryand/or a neurological disorder in the subject.

The methods may comprise changing one or more characteristics of theenvironment in which objects are presented to the subject, including:(i) presenting distracter objects, which the subject is instructed notto interact with; (ii) presenting barriers, real or virtual, that thesubject must move around while attempting to interact or not interactwith the objects; (iii) presenting workspace-defined force-fields, suchas gravity wells; wherein data indicating an effect or no effect of acharacteristic of the environment on the subject's behaviour withrespect to a presented object provide information about brain injuryand/or a neurological disorder in the subject.

The methods may comprise changing one or more characteristics of thesubject's interface in the environment, the one or more characteristicsselected from: (i) providing body-defined force-fields, as a resistance,force, or bias to the subject's limbs; (ii) modulating spatial and/ortemporal alignment of the presented objects relative to the subject'slimb movement; (iii) modulating at least one property of arepresentation of the subject's limbs used to hit or interact with theobjects in the environment, wherein the modulated property is selectedfrom width, length, shape, and a combination thereof; and (iv) providinga representation of the subject's limb geometry.

The methods may comprise obtaining gaze position data as the subjectinteracts with the objects; wherein gaze position data together with theacquired data set provide information about brain injury and/or aneurological disorder in the subject.

In the methods described herein, analyzing may comprise comparing thedata set for a subject with control data. A difference between the dataset for the subject and the control data may indicate a brain injuryand/or neurological disorder in the subject.

Also described herein is a method for obtaining position data and/ormotion data and/or kinetic data of the left and right limbs or portionsthereof of a subject, comprising: presenting objects to the subjectwithin the subject's workspace such that the subject can interact withthe presented objects using either the right or left limb, or portionthereof, of a pair of limbs; using data acquisition apparatus to obtainposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object; andconstructing a data set from the obtained data for a plurality ofpresented objects; wherein presenting objects includes presentingobjects to the subject within the subject's workspace such that two ormore objects are in the subject's workspace simultaneously; or wherein anext object is presented to the subject before the subject can move theright or left limb, or portion thereof, to a selected position afterinteracting with a previous object.

In another embodiment the method may comprise analyzing the data set andoutputting a result that provides information about condition of thebrain and/or neurological status in the subject.

In another embodiment the method may further comprise using the resultto diagnose, assess, or detect brain injury and/or a neurologicaldisorder in the subject.

Also described herein is a method of diagnosing, assessing, or detectingbrain injury and/or a neurological disorder of a subject, comprising:analyzing a data set to determine a brain injury and/or a neurologicaldisorder of a subject; wherein the data set may be obtained by:presenting objects to the subject within the subject's workspace suchthat the subject can interact with the presented objects using eitherthe right or left limb, or portion thereof, of a pair of limbs; usingdata acquisition apparatus to obtain position data and/or motion dataand/or kinetic data of the left and right limbs or portions thereof withrespect to a presented object; constructing the data set from theobtained data for a plurality of presented objects; and analyzing thedata set and outputting a result that provides information aboutcondition of the brain and/or neurological status in the subject;wherein presenting objects includes presenting objects to the subjectwithin the subject's workspace such that two or more objects are in thesubject's workspace simultaneously; or wherein a next object ispresented to the subject before the subject can move the right or leftlimb, or portion thereof, to a selected position after interacting witha previous object.

In another embodiment the data set may be obtained by: presentingobjects to the subject within the subject's workspace such that thesubject can interact with the presented objects using either the rightor left limb, or portion thereof, of a pair of limbs; presenting one ormore distractions to the subject while the subject is interacting with apresented object; using data acquisition apparatus to obtain positiondata and/or motion data and/or kinetic data of the left and right limbsor portions thereof with respect to a presented object; and constructingthe data set by obtaining position data and/or motion data and/orkinetic data of the left and right limbs or portions thereof for aplurality of presented objects.

Also described herein is apparatus for assessing or detecting braininjury and/or a neurological disorder of a subject, comprising: adisplay device that presents objects to the subject over a range oflocations within the subject's visual field such that the subject caninteract with a presented object using a left limb or portion thereof,or right limb or portion thereof, of a pair of limbs; a means thatobtains position data and/or motion data and/or kinetic data of the leftand right limbs or portions thereof with respect to a presented object;wherein the display device displays a representation of the subject'slimbs or portions thereof; wherein position data and/or motion dataand/or kinetic data corresponding to the subject's left limb and rightlimb with respect to presented objects provides information about braininjury and/or a neurological disorder in the subject.

According to another embodiment an apparatus for diagnosing, assessing,or detecting brain injury and/or a neurological disorder of a subjectcomprises: a display device that presents objects to the subject withinthe subject's workspace such that the subject can interact with thepresented objects using either the right or left limb, or portionthereof, of a pair of limbs, wherein the display device displays arepresentation of the subject's limbs or portions thereof; dataacquisition apparatus that obtains position data and/or motion dataand/or kinetic data of the left and right limbs or portions thereof withrespect to a presented object; and computer readable media that directsa computer to perform one or more of: present the objects on the displaydevice such two or more objects are in the subject's workspacesimultaneously; or such that a next object is presented to the subjectbefore the subject can move the right or left limb, or portion thereof,to a selected position after interacting with a previous object; presentthe representation of the subject's limbs or portions thereof on thedisplay device; input and analyze the position data and/or motion dataand/or kinetic data corresponding to the subject's left limb and rightlimb with respect to the presented objects; and output information aboutcondition of the brain and/or neurological status in the subject.

The means that obtains position data and/or motion data and/or kineticdata of the limbs may comprise a mechanical linkage attached to eachlimb, or a mechanical linkage grasped by the subject, or one or moresensors attached to each limb, and related hardware for detecting outputsignals from the one or more sensors.

Also described herein is apparatus for diagnosing, assessing, ordetecting brain injury and/or a neurological disorder of a subject,comprising: a display device that presents objects to the subject over arange of locations within the subject's visual field such that thesubject can interact with a presented object using a left limb orportion thereof, or right limb or portion thereof, of a pair of limbs,wherein the display device displays a representation of the subject'slimbs or portions thereof; data acquisition apparatus that obtainsposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object; andcomputer readable media that directs a computer to perform one or moreof: present the objects and the representation of the subject's limbs orportions thereof on the display device; input and analyze the positiondata and/or motion data and/or kinetic data corresponding to thesubject's left limb and right limb with respect to the presentedobjects; and output information about brain injury and/or a neurologicaldisorder in the subject.

The data acquisition apparatus that obtains position data and/or motiondata and/or kinetic data of the limbs may comprise a mechanical linkage,or one or more sensors adapted to be attached to each limb, and meansthat detects output signals from the one or more sensors, or one or morecameras, or a combination thereof.

The apparatus may be configured to carry out one or more of the methodsdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, and to show more clearlyhow it may be carried into effect, embodiments will now be described, byway of example, with reference to the accompanying drawings, wherein:

FIG. 1A is a schematic representation of the object hitting task,wherein the objects are balls and virtual paddles are located at thesubject's hands.

FIG. 1B is a plot of hand trajectories of a right-affected strokesubject, wherein the black line is a convex polygon that captures theboundaries of the movement trajectories of each hand and captures thearea of space used by each hand during the task

FIG. 1C is a sample of average hand speed during the object hittingtask, wherein successful ball hits are marked with “x”.

FIG. 1D shows performance grids for a control subject (left), aright-side affected stroke subject (middle), and a left-side affectedstroke subject with spatial neglect (right), wherein the x-axisrepresents 10 “invisible” bins from which balls were dropped, and they-axis corresponds to 30 random blocks, where the top row corresponds tothe first random block and the last row corresponds to the last randomblock. Successful hits made with the right hand are in light grey, hitswith the left hand are in dark grey, and misses are shown in white.

FIG. 1E shows the corresponding hits distribution for the subjects ofFIG. 1D, wherein the dashed black vertical line represents hand bias andthe grey dashed line denotes spatial bias.

FIG. 1F shows the percentage of misses in each bin and the correspondingmiss bias for the subjects of FIG. 1D.

FIG. 2A is a plot showing miss bias with respect to hand bias area forsubjects performing an object hitting task as described herein.

FIG. 2B is a plot showing average speed of the left and right hands ofsubjects performing an object hitting task as described herein.

FIG. 2C is a plot showing spatial bias versus hand bias of hits forsubjects performing an object hitting task as described herein.

FIG. 2D is a plot showing number of misses and hand overlap for subjectsperforming an object hitting task as described herein.

FIGS. 3A-D are plots showing hit percentage (A), miss bias (B), spatialbias (C), and median error (D) as a function of age for an objecthitting task. Triangles are female subjects, squares are male subjects.In FIG. 3A, dotted lines are the 5, 50 and 95 quantile regression linesfor the female subject group, and dashed lines are the 5, 50 and 95quantile regression lines for the male subject group. In FIGS. 3C-D, the5 and 95 quantile regression lines are shown as dotted lines, and the 50quantile regression line is shown as a thick dashed line.

FIG. 4 shows a performance grid for a subject with traumatic braininjury (TBI) in an object hitting task. The format is the same as inFIG. 1D, except successful hits made with the right hand are in diagonallines, hits with the left hand are stippled, and misses are shown incrosses.

FIGS. 5A-C are plots showing target object hits (A), distracter objecthits (B), and movement area bias (C) as a function of age for the objecthit and avoid task. Triangles pointing left represent left-affectedstroke subjects, triangles facing right represent right-affected strokesubjects, diamonds represent stroke subjects affected in bothhemispheres, small dots represent control subjects. Solid lines areregression fits for the age effects on total hits (i.e., median scorecorrected for age); dashed lines are at the 5^(th) and 95^(th)percentiles.

FIGS. 6A-B are plots of normalized comparisons of total hits in anobject hitting task versus an object hit and avoid task. Trianglespointing left represent left-affected stroke subjects, triangles facingright represent right-affected stroke subjects, diamonds representstroke subjects affected in both hemispheres. Median scores were set tozero. Values above the median are normalized by the difference betweenthe median and the 95^(th) percentile, whereas values below the medianare normalized by the difference between the median and the 5^(th)percentile. Solid lines are at the 50^(th) percentile; dashed lines areat the 5^(th) and 95^(th) percentiles.

FIGS. 7A-B are plots of number of hits of target objects (A) anddistracter objects (B) in an object hit and avoid task. Large starsdenote TBI subjects, whereas small dots denote control subjects. Solidlines are regression fits for age effects on total hits (i.e., medianscore corrected for age); dashed lines are at the 5^(th) and 95^(th)percentiles.

DETAILED DESCRIPTION OF EMBODIMENTS

Many daily activities require subjects to move and interact with objectsin their environment and involve a broad range of sensory, motor andcognitive processes (i.e., brain functions). Brain injuries and/orneurological disorders may impair one more of these processes,negatively impacting the ability of subjects to perform their dailyactivities. However, the brain injuries and/or neurological disordersthat may be involved cannot be diagnosed, detected and/or assessedsatisfactorily with currently-available procedures.

Of particular difficulty is to quantify diseases or injuries that causemodest deficits in performance. Each sensory, motor and cognitivefunction involves a highly distributed network of cortical and/orsubcortical regions of the brain (Kandel, Schwartz and Jessell, 2000).In many cases, these circuits share and overlap for different brainfunctions, creating a complex interaction across different brainfunctions during activities of daily living. A vascular incident,concussion, traumatic brain injury, or any other neurological disordermay impair neural processing in only a relatively small portion of thebrain or may only impact when two or more brain functions are engagedsimultaneously. The distributed nature of neural processing associatedwith a given function means that impairments in processing in a givenbrain region can be partially compensated for by processing inneighbouring or other regions within the circuit. Deficits inperformance may thus only be observed in more complex situations wherethese compensating portions of the circuit are also engaged orchallenged in other ongoing functions. Thus, deficits in sensory, motoror cognitive function may arise during activities of daily living suchas driving a vehicle, when multiple brain faculties must be engagedsimultaneously, but may not be easily quantified when assessing thepatient using existing clinical assessment tools as these approachestend to focus on one sensory, motor or cognitive function at a time.

The use of actual or simulated activities of daily living such asdriving simulators require multiple sensory, motor, and cognitivefunctions to perform these tasks but such daily activities cannotseparate and disambiguate these myriad functions. As well, certainfunctions are only rarely required in daily activities but are essential(e.g., avoiding a hazard), limiting the number of test events toevaluate subject performance.

Described herein is an apparatus and a method for obtaining data on themotion, position, and/or kinetics of left and right limbs (e.g., arms)of a subject with respect to real and/or virtual objects in theenvironment (i.e., workspace; for example, the region of space that thesubject can reach using one or both hands). The data correspond to thesubject's behaviour with respect to objects in the subject's workspace.The behaviour may include doing nothing with respect to an object, orreacting to and/or interacting with an object. The behaviour may bevoluntary or involuntary (e.g., an autonomic function such as heart rateor blood pressure). While the apparatus is useful for obtaining suchdata from normal, healthy individuals, it is also particularly usefulfor obtaining such data from individuals with brain injury and/orneurological disorders, as it may aid one or more of diagnosis,treatment, management, and therapy for such individuals.

In the embodiments described herein, position and/or motion and/orkinetics of left and right limbs of a pair of limbs maybe monitored, andthe data recorded for analysis. Position and/or motion and/or kineticsof the entire limb (e.g., for the arms: upper arm, lower arm, hand, oneor more fingers, and thumb), or any such segment or portion thereof,individually or in combination, may be monitored. Position, motion,kinetics, and rotation of limb joints (e.g., for the arms: shoulderjoint, elbow, wrist) may also be monitored and the data recorded. Ofcourse, segments and/or joints of the legs may also be monitored. Suchmonitoring may be carried out with data acquisition apparatus, which mayalso be referred to as motion capture apparatus. The data acquisitionapparatus may be mechanical or electronic, or a combination thereof, andobtains and outputs position and/or motion and/or kinetics data of thesubject's limbs in two-dimensional space or three-dimensional space.

In one embodiment, the data acquisition apparatus may comprise wired orwireless sensors adapted to be attached to left and right limbs of apair of limbs of a subject, and related hardware for detecting andreceiving output signals from the one or more sensors. The sensors areused to monitor limb position and/or motion and/or kinetics intwo-dimensional space or three-dimensional space, as the subjectinteracts with objects that are presented to the subject.

In another embodiment, limb position and/or motion and/or kinetics intwo-dimensional space or three-dimensional space may be monitored byusing data acquisition apparatus comprising one or more cameras, as thesubject interacts with objects that are presented to the subject.

In another embodiment, the data acquisition apparatus may comprise arobotic/mechanical linkage used to monitor position and/or motion and/orkinetics of the limbs. Such linkages maybe grasped by the subject duringuse, or they may be attached to the limb (e.g., KINARM, U.S. Pat. No.6,155,993 issued 5 Dec. 2000 to Scott). Robotic/mechanical linkagesprovide the ability to apply physical loads to the limb of portionthereof, as resistance to or bias against certain motions of the limb,or to simulate contact with virtual objects presented to the subject.

In the embodiments described herein objects presented to the subject maybe real objects or virtual objects. Virtual objects may be displayedusing, e.g., a display screen and/or projector, or using a virtualreality or augmented reality system.

In the embodiments described herein, subjects interact with presentedobjects using both limbs, or portions thereof, of a pair of limbs.However, the embodiments may also be applied to a single limb or portionthereof. Further, data may be obtained for right and left limbs, orportions thereof, separately, or simultaneously, using the embodimentsdescribed herein.

As used herein, the term “virtual reality” or “VR” refers to anartificial environment into which a subject may completely or partiallyimmerse him/herself, and/or with which the person may interact. Theartificial environment may be provided in 2 or 3 dimensions (i.e., 2D or3D), using any suitable technology. For example, the artificialenvironment may be computer-generated and adapted (e.g., projected) in amanner that allows the subject to immerse into and/or interact with theenvironment.

As used herein, the term “augmented reality” or “AR” refers to anartificial environment that includes the features described above forVR, but it also includes aspects of the real world as part of thesensory experience. For example, simultaneous, overlapping views of thereal world may be combined with computer-generated images.

In the methods and apparatus described herein, the proprioceptive andvisual information obtained retain the natural relationship between thesensory modalities, in that limb afferent feedback of hand position isin register with visual information of its position. This is differentfrom systems that use avatars, such as in computer-based systems (e.g.,games such as Wii® and Kinect®), where the subject uses visual feedbackof an object or avatar on the screen, but the proprioceptive informationstill conveys a location of the limb. In this case, the subject mustlearn how to align and coordinate these two forms of sensory feedback.

The methods and apparatus described herein do not employ hardware,platforms, etc., typically used in applications such as, for example,computer and video gaming and computer-based graphics. For example, suchapplications may employ hardware such as a mouse or a joystick.Accordingly, diagnosis, assessment, or detection of brain injury and/ora neurological disorder of a subject as described herein avoids any biasthat may arise in subjects who are familiar or experienced with suchhardware, platforms, etc. The contents of all references, pending patentapplications, and published patents cited throughout this applicationare hereby expressly incorporated by reference.

Embodiments are further described by way of the following non-limitingexamples:

EXAMPLE 1 Object Hitting Task

Described herein is an object hitting task, which is an example of amethod for assessing or detecting brain injury and neurologicaldisorders. The object hitting task requires a subject to hit objectsthat move in the subject's environment (i.e., the subject's visual fieldor workspace) using either limb of a pair of limbs, such as the arms. Anembodiment is shown schematically in FIG. 1A, and includes mechanicallinkages to obtain position and/or motion and/or kinetics information ofthe subject's arms, and a VR or AR display device as the subject'sworkspace. Virtual paddles are displayed as located at the subject'shands and the paddles are moved by moving the arms and/or hands. Objects(e.g., balls) are presented to the subject in the display, and thepaddles are used to hit the balls away from the subject. To begin, onlyone ball is presented at a time and the ball moves relatively slowlytowards the subject. With time, the rate at which balls are presentedand the speed with which they move through the workspace increases sothat after a period of time (e.g., several minutes) balls may moverapidly through the workspace (e.g., in as little as one second), andthere may be many balls moving through the workspace at any moment.Most, but not all, of the balls pass through an area of the workspacethat is reachable by both hands, such that the subject is forced tochoose which hand to use to hit those balls.

The mechanical apparatus used to obtain position and/or motion and/orkinetics information of the arms may be, for example, the KINARMExoskeleton robot (BKIN Technologies Ltd., Kingston, Ontario) or theKINARM End-Point robot, (BKIN Technologies Ltd., Kingston, Ontario).Both KINARM robots are four-bar linkages that move with two degrees offreedom substantially in the transverse plane. The subject's arms areconnected to the KINARM Exoskeleton robot via forearm and upper armtroughs such that the robot's joints are substantially aligned with thesubjects' shoulder and elbow joints. In contrast, the subject interactswith the KINARM End-Point robot by grasping a handle, such that therobot's handle is substantially aligned with the subject's hand. Bothsystems can provide force/haptic feedback to simulate ball contact andincorporate two-dimensional virtual/augmented reality systems forvisually presenting the balls to the subject.

In one embodiment the balls move within the workspace in the transverseplane and their locations in space are varied so that some balls move tothe left of the subject's midline and other balls move to the right ofthe subject's midline, although some balls may also be located on thesubject's midline. The number of balls to the left may be equal to thenumber of balls to the right of the subject. This embodiment requires asubject to identify the location and speed of each ball moving in theworkspace, select one of the two arms with which to hit the object(using the virtual paddles), and then execute a motor action to hit theball. Data collected relate to which limb (left or right) is used foreach ball, and other parameters such as mean hand speed and ball contactforce.

An integral part of this task is the selection of the limb used to hitthe object for those objects that can be reached by both limbs. Incontrol subjects, there is substantially equal use of the two limbs andthe point of transition between using the left and right limbs tends tobe near the middle of the workspace (although there may be a small biasto using the right hand more and shifting the transition to the leftside in right-handed individuals, and vice-versa in left-handedindividuals). Other parameters of the task, such as mean hand speed andball contact force, are characterized by a high degree of symmetry forcontrol subjects.

However, in subjects with disorders or diseases such as stroke there canbe differences in the motor skills of the two limbs. The task quantifiesthese differences by recording data calculating a range of parametersrelated to how the hand/limb hits the objects and the pattern ofmovement of each limb within the workspace.

A unique feature of the task is that not only are asymmetries in use ofthe two limbs quantified, but also how and where the two limbs are usedin the workspace. For many stroke subjects, there is a natural trade-offas to how often a limb is used to hit an object and the spatialtransition point where one limb tends to be used more than the other.Subjects that predominantly use their left hand to hit objects tend tohave a transition point located on the right side of the workspace (SeeFIG. 2C).

However, some stroke subjects do not show this trade-off and insteadshow preferential use of one limb, but no shift in the spatialtransition point, or a shift in the same direction as the handpreference. FIG. 1D (right panel) shows an example of one such subjectthat used the right hand more than the left, but the spatial bias waslocated on the right side of the workspace. This subject also displayeda greater number of misses to the left versus the right. Importantly,this subject was identified as having spatial neglect using the BIT test(BIT score 105). Several other subjects with clinically defined spatialneglect also showed this pattern of behaviour (Solid triangles in FIG.2C). These results demonstrate how the object hitting task describedherein can identify different patterns of behaviour resulting from braininjury.

Variations of the Task

In one embodiment the object hitting task is a basic task that requiresboth limbs to be engaged in ongoing motor actions and involves thesubject planning and selecting for impending motor actions with eachlimb, and thus provides key information on these processes. However,this basic task creates a foundation for quantifying other aspects ofbrain function, which in other embodiments may include strategicallymanipulating one or more features of the task.

In such embodiments, variations in the object hitting task permit moredetailed and specific examination of different aspects of a subject'sperformance. For example, the task may be performed with smaller paddlesto enhance the difficulty of hitting the objects, to emphasize theimportance of movement accuracy to successfully perform the task. Suchadditional challenges in the task stress associated circuits in thebrain involved in that process, and/or impact upon other ongoingprocesses due to overlap in neural processing involved in these brainfunctions. Thus, a change in performance across variations of the taskprovides information on brain processes that are specifically challengedby the task variation, but also on brain processes that are sharedacross two or more tasks.

Another variation of the task is to include distracters, that is,objects in the workspace that are not meant to be contacted by thesubject. Distracters may have different characteristics than objectsmeant to be contacted by the subject. For example, a distracter may be adifferent colour and/or shape, or move in a different trajectory orspeed within the workspace, than an object meant to be contacted by thesubject. For example, a subject could be instructed to hit circularobjects, and not to hit square objects. Such distracters increase thecognitive requirements of the task by requiring subjects to identify theproperties of each object before deciding whether to hit the object ornot. A further variation may be to have a subject hit circular objectsbut specifically avoid hitting any of the distracters in the workspace.In such a hit and avoid task the use of distracters demands greaterattention of the subject and requires inhibitory processes in the brainso as to avoid contact with the distracters. In another embodiment adistracter may include presenting audio (i.e., sound) to the subject,which may or may not have an association with either the subject'sbehaviour and/or a presented object.

Another variation may include adding barriers to the workspace, suchthat the subject must navigate around the barriers to interact with theobjects.

Another variation may include adding one or more ‘gravity’ wells orother force-fields in various locations within the workspace. Gravitywells or other force-fields may be of uniform strength or they may varyin strength (of force) from one to another. Such force-fields aredefined with respect to the subject's workspace.

Another variation may include adding a delay to the visual feedback(e.g., a display screen) of where the limbs are in the workspace.

Another variation may include changing the physical mapping between thelimbs and the workspace (e.g., visual feedback may be provided on ascreen in front of the subject, rather than as a VR setup).

Another variation may include making all objects stationary.

Another variation may have objects appear for a brief period of time.

Another variation may have only one object presented at time and appearrapidly after the previous object has disappeared.

Another variation may include making all objects visible immediately.

Another variation may require more complex cognitive decisions such ashitting an object after a different object has been displayed. Forexample, the task might require the subject to hit any object thatappears following the presentation of a circular object.

Another variation may include modifying one or more properties of thesubject's interface (i.e., properties of the display and/or mechanicaland/or physical attributes of the subject's environment) to make itasymmetric with regard to the difficulty required to hit objects. Forexample, the paddles used to hit objects may be of different sizes foreach limb, or include a representation of the limb's geometry (e.g.,upper arm, forearm, and/or hand).

Another variation may include adding a limb-based force-field or“body-defined” force field, such as viscosity (e.g., to resist limbmovement; to make the limb it feel like it is moving through molasses)or by adding an inertial load (e.g., to make the limb or portionthereof, such as the hand, feel like it is heavier). Such force-fieldsare defined with respect to the subject (e.g., limb velocity).

Another variation may include making the midline of the workspacesubstantially aligned with the midline of the subject.

Another variation may include gaze-tracking of the subject during thetask including any variation thereof, such as the variations describedabove. Gaze direction may then be compared to the subject's movements,to determine, for example, if an object was not hit, did the subjectlook at the object or not.

Another variation may include coupling (e.g. mechanically, visually orthrough other means) two limbs together so that the limbs must be usedtogether in a coordinated fashion to hit an object. For example,coupling may require the subject to grip an effector with both handssimultaneously, such that moving the effector to hit an object requirescoordinated movement of both limbs.

Another variation may include asking the subject to stand whileperforming the task.

Another variation may include having the subject perform the task withonly one limb.

Another variation may include recording data about the subject's posturewhile performing the task (e.g., using a force-plate).

Another variation may include using a motion tracking system to trackposition and/or motion and/or kinetics of the limbs (e.g., using passiveor active markers, or a markerless system).

Another variation may include using force feedback to control theposition and/or motion and/or kinetics of one or more properties of thesubject's interface.

Other variations may include other means to engage other regions of thesubject's brain while performing this task.

For a given variation of the task (as described above), differences intarget characteristics may be introduced to avoid learning effects;however, providing those differences instances with a substantiallyequal level of difficulty ensures that the results are meaningful and/orcomparable. For example, when introducing one or more distracter objectsin the workspace, the distracter shape(s) may be chosen to besubstantially different from the target shapes. Each such variation inthe task provides further information on its own, whereas comparisons ofperformance across task variations provides additional information onhow each component of the task directly impacts behavioural performance.

In some prior tasks, objects are presented to subjects in a way thatallows the subject to recover from a presentation of an object and/orprepare for presentation of a next object. For example, given sufficienttime, a subject may prepare for presentation of a next object in one ormore ways, such as mentally (e.g., by concentrating, anticipating thenext object, etc.), and/or physically (e.g., by moving one or both limbsor portions thereof to a selected position (i.e., a new, substantiallydifferent position, including, e.g., a ready position, or a definedstarting position)). Insofar as this may be a drawback for someassessments, embodiments of certain tasks described herein decrease oreliminate the duration of time a subject has to recover frompresentation of an object, and/or decrease or eliminate duration of timea subject has to prepare for the presentation of a next object. Suchembodiments can provide substantially more information about a subject'ssensory, motor, and cognitive brain functions, compared to tasks thatpermit recovery and/or preparation time in respect of presented objects,and may enhance diagnosis, assessment, and/or detection of brain injuryand/or neurological disorders.

As used herein, the term “distraction” includes any stimulus presentedto a subject that may challenge or interfere with the subject's abilityto interact with an object. For example, a distraction may include anyof the distracters discussed herein, or any of the variations of thetasks discussed herein that provide such a challenge to the subject.

EXAMPLE 2 Evaluation of Stroke Subjects

Participants

Stroke subjects were recruited from the stroke rehabilitation wards atProvidence Care, Saint Mary's of the Lake Hospital site in Kingston,Ontario, and from Foothills Hospital in Calgary, Alberta. The strokepatients had a single stroke that resulted in cortical, subcortical,cortical-subcortical, brainstem, cerebellar, or mixed lesions. Thesubjects were broadly categorized into right affected (RA) or leftaffected (LA) based on the most affected side of the body. Age-matchedcontrol subjects (people with no neurological disorders) were recruitedfrom the community. Participants were excluded if they could notunderstand the task instructions. Each subject underwent a typicalstroke assessment and one robotic session (described below), whereseveral tasks were performed for each arm, including the object hittingtask.

Clinical Evaluation

The procedure and the documented clinical parameters that were used inthis study have previously been described [Dukelow et al., 2010, Coderreet al., 2010]. The clinical evaluations were performed by the studyphysician or physiotherapist. The clinical parameters included thehandedness score, Behavioural Inattention Test (BIT), Mini-Mental StatusExam (MMSE), Montreal Cognitive Assessment (MoCA), FunctionalIndependence Measure (FIM), and Chedoke-McMaster Stroke Assessment Scalefor hand and arm (CMSAh and CMSAa). Previous reports showed that controlsubjects obtained perfect scores with each limb on both the arm and handportion of the CMSA (CMSAa and CMSAh) [Coderre et al., 2010], therefore,in this study the CMSA clinical assessment was not performed for thecontrol group.

Robotic Assessment

Performance of subjects during the task was monitored using the bimanualKINARM exoskeleton robot, (BKIN Technologies Ltd., Kingston, Ontario).The details of the KINARM robot setup were previously described [Dukelowet al., 2010, Coderre et al., 2010]. Briefly, a subject was seated in awheel-chair base while their arm segments (arms, forearms and hands)were placed in plastic arm troughs attached to an adjustable four-barlinkage of the KINARM. The experimenter adjusted the linkage and thetroughs for each subject insuring comfortable and correct position ofthe subject during the experiment. The KINARM allowed free horizontalhand movements while providing full gravitational support for subject'sarms. The task's visual targets were projected via mirrors onto avirtual horizontal workspace positioned in the same plane as subject'sarms. The virtual environment was achieved by occluding direct vision ofa participant's arms and projecting hand position on the screen as twogreen paddles, and the objects (“hit targets”) were presented as redballs.

Experimental Task

In the object hitting task subjects were instructed to use their rightand left hands, represented as green paddles, to hit red balls that weremoving towards them on the screen (see FIG. 1A). The objective of thetask was to hit as many balls as possible. The balls appeared on thescreen from 10 different bins, whose locations were not shown. Each taskconsisted of continuously running 30 random sets. Ten balls were used ineach set, and each ball appeared from one of the 10 “invisible” bins inrandom order. Consequently, the game consisted of a total of 300 ballsfalling continuously on the screen. The number of balls that appear onthe screen and the speed of the ball movement increased as the taskprogressed. Force feedback was generated by the KINARM robot each time apaddle hit a ball. During the task, positions of the hands and activeballs were recorded with a sampling frequency of 200 Hz (one sampleevery 0.005 seconds).

Data Analysis

Data analyses were performed using MATLAB (Mathwork, Inc.,Massachusetts, USA). First, the control data was analyzed and nineparameters were developed to quantify task performance, hand usage, andmotion. Then a non-least-squares linear regression was performed toidentify age-dependent parameters and to eliminate trend in the data.The resulting values for the nine parameters for the control data wereseparated using five quantiles (5%, 25%, 50%, 75%, 95%). Stroke patientsthat fell out of the 5-95% inter-quantile range of the control groupwere considered as impaired in terms of their performance.

Parameters

Ten parameters were developed to characterize performance and toquantify task performance, hand usage, and motion.

Number of misses: captures the overall performance of a subject. Thisparameter simply sums up all the missed balls during the task for eachbin. A ball hit is valid only when a subject hits the ball with a paddleand the ball leaves the display area either at the top or on one of thesides. Alternatively, overall performance may be quantified by object ortarget hits, or based on a percentage of misses or hits.

Miss bias: quantifies any bias of misses towards one side or another. Itis computed by counting the number of misses for each of the ten binsand then calculating the weighted mean of the resulting distributionover the ten bins.

Hand bias of hits: captures participant's preference and ability forusing one hand over the other for successfully hitting the balls (handdominance). It is the normalized difference between the total number ofhits with right (RH) and left (LH) hands: (RH hits−LH hits)/(RH hits+LHhits).

Hand overlap or hand selection overlap: captures how effectiveparticipants are at using both hands and how often they overlap theirhands (i.e., hit the balls with the right hand in the left area of thescreen, and vice versa). The parameter is computed by calculating thesum of absolute differences between the right and left hand hits in binswhere both hands made hits. An alternative method is by counting thenumber of times that two successful hits of balls from a given bin werehit by different hands (i.e., ball hit by left hand and the next ballfrom that bin was hit by the right hand, or vice versa). The final countis then divided by the total number of hits.

Spatial bias of hits or hand transition: shows where the subject'spreference for using one hand over the other switches in the workspace.To compute this bias, first, the integral is taken of differencesbetween left and right hand hits for each bin. Then the resulting dataare interpolated using a cubic spline, and the spatial bias of hits isthe peak of the resulting curve. Alternatively, this parameter may becomputed by taking the mean of two values: the right hand and the lefthand weighted means of hit distributions. The weighted mean of hitdistributions for each hand is calculated independently for each handusing a subset of bins, including only those where both hands made hits(overlapping bins) plus one additional bin on each side of the overlapbins. In the case where no overlap occurs, the subset of bins usedincludes the right-most bin in which hits were made by the left hand andthe left-most bin where hits were made with the right hand.

Hand area or hand movement area: captures the area of space used by eachhand during the task. It is computed as the area of the convex hull,which is a convex polygon that captures the boundaries of the movementtrajectories of each hand. The hand area parameter is computed for eachhand separately resulting in two parameters.

Hand bias area or movement area bias: shows the bias in using one handover the other with respect to the total area of the hand movement. Itis computed by subtracting the hand area of the left hand from the handarea of the right hand and then normalizing by the total area of bothhands (RH−LH)/(RH+LH).

Mean hand speed: is computed as the mean of the hand speed at each timestep (every 0.005s) of the experiment. The parameter is computed foreach hand separately resulting in two measures.

Hand bias speed: quantifies the bias in using one hand over the otherwith respect to the average hand speed. It is computed by subtractingthe mean hand speed of the left hand from the mean hand speed of theright hand and then normalizing by the sum of the mean hand speeds ofeach hand RH−LH)/(RH+LH).

Median error (ball %): quantifies the point in the task where thesubject missed half of the balls. It is computed by finding the ball (ortime index) when half of the misses were made by the subject and thencompute the percentage of total possible misses. Large scores mean thatthe subject performed relatively well when the task was easy and failedpredominantly only at the end of the task when the task difficulty wasgreatest.

Results

Participant Pool

Data were collected from 35 stroke subjects (18 left- and 17right-affected) and 39 age-matched control subjects. Table 1 shows thesummary of collected demographic and clinical data for all subjects. Themajority of the subjects were right-hand dominant (n=66 out of 74), andthere was no difference in the distributions of age across the threeparticipant groups (Kolmogorov-Smirnov (KS), P>0.05). The majority ofthe stroke patients had ischemic stroke (69%) and predominantly in thecortical area of the brain (49%). Five out of 35 stroke subjects hadspatial neglect (BIT score<130).

Clinical Measures

The clinical measures for the stroke participants are presented inTable 1. There were no differences between left- and right-affectedparticipants on the FIM (cognitive, motor and total), MMSE, or MoCAscores (Wilcoxon 2-sided rank sum test, P>0.05). However, there was adifference between left- and right-affected participants on the BIT(Wilcoxon 2-sided rank sum test, P<0.01) score: left-affected hadsignificantly lower scores. Based on CMSAa and CMSAh scores, theparticipants obtained worse scores with their affected arm as comparedto their unaffected arm (Wilcoxon 2-sided signed rank test, P<0.01).

Robotic Assessment

Individual Subject Exemplars

The performance plots and results for some of the parameters are shownfor exemplar data in FIGS. 1D-F. The exemplar data consist of a controlsubject (left), a right-affected stroke subject (middle) and a left-sideaffected stroke subject with spatial neglect (right).

The performance grid of the control subject illustrates a pattern of anormal performance. It shows small number of misses, mostly on the farleft or far right sides of the screen and mostly towards the end of thetask, when ball speed is high. FIG. 1E shows the corresponding hitsdistribution for the control subject and two parameters: hand bias(dashed line) and spatial bias (dotted line). The control subject has ahand bias and spatial bias near, indicating symmetric use of the hands.The miss bias for the control subject (FIG. 1F) is slightly shifted tothe left, indicating that more misses were observed on the left side ofthe field, which may be due to the fact that this control subject isright-hand dominant.

The first stroke subject (in the middle) has different spatial and handbias. The subject clearly prefers using the left hand over the rightstroke-affected hand. The negative hand bias indicates that the subjecthit more balls with the left hand, and the positive spatial biasindicates that the subject covered more space of the screen with theleft hand than with the right hand. The miss bias for this strokesubject is near the center and shows that balls were missed near equallyon both sides of the screen.

The second stroke subject (on the right) shows equal spatial and handbias, however they are shifted to the right and the screen area on theleft is almost completely untouched. This supports the clinicalassessment results, which indicates that this stroke participant hasspatial neglect (BIT score=129). This negative miss bias indicates thatmost of the balls were missed on the left side of the screen, such thatin bins 1, 2 and 3 the balls were almost completely missed.

Age Effect

A regression analysis, using non-least-squares linear regression wasperformed to identify which parameter values are affected by the age ofthe subject. The results indicated that only the “number of misses”parameter showed a slope at the 1% level of significance and, therefore,is affected by the age of a subject. Consequently, in further analysisthe data of the “number of misses” parameter were de-trended.

Performances of Control and Stroke Groups

Table 2 shows the percentage of stroke participants that were identifiedas different from controls based on their affected arms. The parametersthat identified the largest number of stroke participants as abnormalwere the following: hand overlap (94% of left- and 41% ofright-affected), hand bias area (89% of left- and 41% ofright-affected), hand bias of hits and hand bias speed (83% of left- and59% of right-affected). The parameters that identified the least numberof stroke participants as abnormal were the following: number of misses(12% of left- and 28% of right-affected), hand area right hand (24% ofleft- and 11% of right-affected), and miss bias (35% of left- and 11% ofright-affected).

FIGS. 2A-D highlight some of the range of performance across subjectgroups.

FIG. 2A shows miss bias with respect to hand area bias. The controlsubjects tend to have hand area bias close to zero; whereas majority ofright-affected stroke participants showed negative bias andleft-affected subjects showed positive bias reflecting the fact thesesubjects had larger hand areas for their non-affected hand than fortheir affected hand. Similarly, the miss bias, although as noteffectively, separates left-affected and right affected strokeparticipants into two groups, such that left-affected subjects are tothe left of the screen (negative bias, more misses on the left side) andright-affected subjects tend to be on the right side of the screen(positive bias, more misses on the right side).

FIG. 2B displays the average speed for the left and right hands. Therewas a broad range of speeds utilized by control subjects, ranging from0.06 m/sec to 0.27 m/sec. However, there was a strong correlationbetween speed of two hands, indicating that control subjects moved botharms either slowly or both arms quickly. The majority of the strokeparticipants, on the other hand, showed slower speed for their affectedarm than for the non-affected arm. Furthermore, there were often greaterdifferences in the speed of the two hands.

FIG. 2C shows results of the spatial bias versus hand bias of hits.Similar to other biases, control subjects have spatial and hand biasesof hits close to zero. Left-affected stroke participants showed negativespatial bias because they made more hits and covered more space withtheir non-affected, right hand. Similarly, majority of theright-affected stroke participants made more hits and covered more spacewith their non-affected left hand which resulted in positive spatialbias. The hand bias of hits was negative for the left-affected strokeparticipants and positive for the right-affected stroke participants,since subjects tend to make more hits with their non-affected hand.Consequently, results of typical stroke patients and controlparticipants form a line, such that controls are in the center,right-affected participants are on the right side and left-affectedparticipants are on the left side of the line. However, stroke patientswith specific deficits fall out of this pattern. For example, theexemplar participant from FIG. 1D-F (middle) has positive hand andspatial bias of hits and fell out of the “line pattern” (FIG. 2C, theright most solid triangle).

FIG. 2D shows the number of misses and hand overlap. There was a largerange of values for the overlap among the control group. However, theparameter values were much lower among the stroke participants. Thedifference between the values was especially profound between thecontrols and the left-affected subjects, such that 94% of theirperformance was abnormal (Table 2). This indicates that strokeparticipants not only made fewer hits, but they did not overlap hands asoften as control participants, especially the left-affected strokegroup.

Assessing Neurological Impairments

The developed parameters were compared to a clinical FunctionalIndependence Measure (FIM) scores collected for the stroke subjects.Table 2 shows the results of the Spearman correlation between allparameters and the three FIM categories scores (motor, cognitive, total)and the BIT scores.

EXAMPLE 3 Evaluation of Effect of Age

The effects of age, gender, and handedness was examined in our cohort ofcontrol subjects. Hand speeds were filtered using sixth order doublepass Butterworth low pass filter with cut-off frequency of 10 Hz.Initially, the values for the miss bias, spatial bias, hand bias, totalhand area, total hand area bias, hand speed and hand speed bias wereflipped for left handed subjects. Subsequently, each parameter wastested for normality and parameters that were identified as not normallydistributed (Lilliefor's composite goodness-of-fit, p<0.01) weretransformed using a log transform (hand selection overlap and hand speedof the non-dominant hand). Then, for each parameter a non-least-squareslinear regression was done to identify age-dependent parameters and toidentify if there was a difference between males and females(Kolmogorov-Smirnov goodness-of-fit hypothesis test, p<0.01). If therewere no differences, data from each gender or limb were combined;otherwise data were studied separately (hit percentage and total handarea dominant hand). The separated data was re-tested for normality andage effect. The regression analysis identified two parameters that aregender-affected: hit percentage and total hand area of dominant hand;and four age-affected parameters: hit percentage (males and females)(FIG. 3A), miss bias (FIG. 3B), spatial bias (FIG. 3C), and median error(FIG. 3D).

EXAMPLE 4 Evaluation of Traumatic Brain Injury (TBI) Subjects

A cohort of 12 subjects with traumatic brain injury (nine severe, twomoderate, one mild, based on the Glasgow Coma Scale) were assessed usingthe object hitting task. Data for one subject is shown in FIG. 4. Thissubject's TBI history included loss of consciousness for several minutesdue to the injury and was a “9” on the Glasgow Coma Scale when firstassessed clinically with both a focal and diffuse axonal injury.

The subject was assessed with the object hitting task, as describedabove, 23 days after the injury and at this point had normal Fugl-Meyerscores for each limb (66), and normal cognitive function based on theMOCA (>27). In the object hitting task, the subject displayed severalatypical patterns of behaviour, including many missed objects and thesemisses are asymmetric with a greater number on the left side of the workspace as well as a preference for using the right hand as compared tothe left hand for hitting the objects (see FIG. 4).

EXAMPLE 5 Object Hit and Avoid Task with Stroke Subjects

Described herein is an object hit and avoid task, which requires asubject to hit certain target objects (e.g., vertical rectangle andcircle) and not hit other distracter objects (e.g., squares andtriangles) using either limb of a pair of limbs, such as the arms. As inExample 1, virtual paddles are displayed at the position of thesubject's hands and the number and speed of objects presented to thesubject increases with time during the task. Target objects can be hitwith the paddles including haptic feedback of contact force, whereasdistracter objects simply pass through the paddles to remind subjectsthat these are errors. In total there were 200 target objects to hit and100 distracters objects not to hit. A large cohort of control subjects(154) was examined to quantify healthy performance, and regressions wereperformed to quantify age effects on performance.

A cohort of 12 stroke subjects was also assessed with this task. FIG. 5Ashows the number of hits that subjects made with the target objects.Eight of the 12 stroke subjects were lower than healthy controlsubjects. FIG. 5B shows the number of hits that subjects made with thedistracter objects. Seven of the 12 stroke subjects hit more distractertargets as compared to control subjects. Ten of the 12 stroke subjectseither hit fewer target objects and/or more distracter objects. FIG. 5Cshows the movement area bias for stroke and control subjects. Many ofthe stroke subjects show larger biases than control subjects. Notably,three of the four left-affected subjects (triangles pointing left) hadpositive biases larger than controls, denoting that the area of spaceused by their right arm was much larger than the area used by their leftarm. In contrast, all six right-affected stroke subjects (trianglespointing right) had movement area biases that were more negative thancontrols. Thus, this parameter quantifies how performance was biased,with less use of the affected limb as compared to non-affected limb.

EXAMPLE 6 Comparison of Object Hit Task with Object Hit and Avoid Task

Comparison of performance across tasks provides another useful measureof brain function. FIG. 6A shows the number of hits for the object hittask versus the number of hits of target objects in the object hit andavoid task for 12 stroke subjects. The data has been normalized to the95^(th), median, and 5^(th) percentiles for age-matched controls. Valuesabove the median are normalized by the difference between the median and95^(th) percentile, whereas values below the median are normalized bythe difference between the median and the 5^(th) percentile. The figureshows that eight stroke subjects were different from controls in bothtasks, and one subject was different from controls only for the objecthit task. In general, stroke subject performance tended to be worse forboth tasks as compared to controls (r=0.89).

A more complex pattern of deficits was observable when quantifying otheraspects of performance. FIG. 6B quantifies the relative scores for themovement area bias for the object hit task and the object hit and avoidtask. Ten of the 12 stroke subjects exhibit differences from controlsubjects on one or both tasks: seven stroke subjects were different fromcontrols for the object hit task, whereas nine stroke subjects weredifferent from control subjects in the object hit and avoid task.Although the correlation was high for performance across the two tasks(r=0.94), only six subjects failed both tasks. One subject had asignificant positive bias for the object hit task which requires hittinga total of 300 targets, but was well within the normal range for theobject hit and avoid task, whereas three other subjects displayed thereverse pattern.

These differences are important. For some subjects, the object hittingtask emphasizes speed as 300 targets must be hit in a given time period,whereas only 200 targets must be hit for the object hit and avoid task(and avoid the 100 distracter targets). Thus, the increased motordifficulty is associated with poorer performance with regards tosymmetry of limb movements for the one subject. In contrast, deficits inlimb symmetry were only observed for the object hit and avoid task inthree subjects. In this case, limb motor symmetry became worse due tothe addition of a cognitive load. Therefore, the engagement of anadditional sensory, motor, and/or cognitive function can reveal animpairment in another sensory, motor, and/or cognitive function.

EXAMPLE 7 Object Hit and Avoid Task with Traumatic Brain Injury Subjects

Described herein is the use of an object hit and avoid task (as inExample 5) to quantify brain dysfunction in subjects with traumaticbrain injuries. A cohort of eight subjects was tested in this task.FIGS. 7A and 7B show hits for target objects (7A) and distracter objects(7B). Five of the eight subjects hit fewer target objects and/or moredistracter objects than healthy controls. In one case, a subject hitmany more (43) distracter targets than did healthy controls, but waswithin the normal range for hitting target objects. The subjectunderstood the instructions as the percentage of hit objects was higherthan distracters (˜75% of targets and ˜40% of distracters). However, thesubject clearly had difficulty avoiding the distracters. Three othersubjects (all <25 years of age) displayed the opposite pattern with nodifficulties missing the distracters but reduced hits of target objects.

EQUIVALENTS

Those skilled in the art will recognize or be able to ascertain variantsof the embodiments described herein. Such variants are within the scopeof the invention and are covered by the appended claims.

REFERENCES

-   Coderre, A. M., Abou Zeid, A., Dukelow, S. P., Demmer, M. J.,    Moore, K. D., Demers, M. J., H., Herter, T. M., Glasgow, J. I.,    Norman, K. E., Bagg, S. D. and Scott, S. H. (2010) Assessment of    upper-limb sensorimotor function of subacute stroke subjects using    visually-guided reaching. Neurorehabiliation and Neural Repair    24:528-541.-   Dukelow, S. P., Herter, T. M., Moore, K. D., Demers, M. J.,    Glasgow, J. I., Bagg, S. D., Norman, K. E., Scott, S. H. (2010)    Quantitative Assessment of Limb Position Sense Following Stroke.    Neurorehabiliation and Neural Repair 24:178-187.-   Kandell, E. R., Schwartz, J. H., Jessell, T. M. (2000) Principles of    Neural Science, 4^(th) ed. McGraw-Hill, New York.-   Teasell, R., Bayona, N., Heitzner, J. (2003) Clinical consequences    of stroke. In: Teasell, R. et al., Stroke Rehabilitation    Evidence-Based Review, 6th edition [monograph on the Internet].    London, ON: Heart & Stroke Foundation of Ontario and Canadian Stroke    Network.-   Van Deusen, J., Brunt, D. (1997) Assessment in Occupational Therapy    and Physical Therapy. Philadelphia: W.B. Saunders Co.

The invention claimed is:
 1. A method for diagnosing, assessing, ordetecting brain injury and/or a neurological disorder of a subject,comprising: presenting objects to the subject within the subject'sworkspace such that the subject can choose to interact with thepresented objects using either the right or left limb, or portionthereof, of a pair of limbs; using data acquisition apparatus to obtainposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object;constructing a data set from the obtained data for a plurality ofpresented objects; and analyzing the data set and outputting a resultthat provides information about condition of the brain and/orneurological status in the subject; wherein analyzing comprisesdetermining from the position data and/or motion data and/or kineticdata whether the left limb or right limb was used with respect to apresented object, and repeating the determining for a plurality ofpresented objects to produce the acquired data set; wherein presentingobjects includes presenting objects to the subject within the subject'sworkspace such that two or more objects are in the subject's workspacesimultaneously; or wherein a next object is presented to the subjectbefore the subject can move the right or left limb, or portion thereof,to a selected position after interacting with a previous object.
 2. Themethod of claim 1, wherein determining includes: relating location of apresented object within the subject's workspace to the location of theleft limb or right limb that was used to interact with the presentedobject; and repeating the relating for a plurality of presented objectsto produce the acquired data set.
 3. The method of claim 1, furthercomprising: recording one or more autonomic functions of the subjectwith respect to a presented object; and repeating the recording for aplurality of presented objects; wherein data for the one or moreautonomic functions together with the acquired data set provideinformation about brain injury and/or neurological disorder in thesubject.
 4. The method of claim 3, wherein the one or more autonomicfunctions are selected from heart rate and blood pressure.
 5. The methodof claim 1, further comprising: presenting the objects to the subjectusing virtual reality or augmented reality; whereby the virtual realityor augmented reality is two-dimensional or three-dimensional.
 6. Themethod of claim 1, wherein: the data acquisition apparatus comprises amechanical linkage; wherein the subject's left and right limbs orportions thereof are in contact with the mechanical linkage.
 7. Themethod of claim 6, wherein the mechanical linkage is adapted to be heldwith the left and right limbs or portions thereof.
 8. The method ofclaim 6, wherein the mechanical linkage is adapted to be attached toleft and right limbs or portions thereof.
 9. The method of claim 1,wherein: the data acquisition apparatus comprises wired or wirelesssensors adapted to be attached to left and right limbs of a pair oflimbs of a subject, and a detector that detects output signals from theone or more sensors or one or more cameras, to obtain position dataand/or motion data and/or kinetic data of the left and right limbs orportions thereof with respect to a presented object.
 10. The method ofclaim 1, further comprising: obtaining kinetic trajectory data of a limbwith respect to a presented object; wherein kinetic trajectory dataprovide information about brain injury and/or a neurological disorder inthe subject.
 11. The method of claim 1, further comprising: obtainingspeed and/or velocity data of a limb with respect to a presented object;wherein the speed and/or velocity data provide information about braininjury and/or a neurological disorder in the subject.
 12. The method ofclaim 1, wherein the presented objects include at least onecharacteristic selected from: (i) presented objects are stationary; (ii)presented objects are moving; (iii) presented objects are moving atdifferent speeds; (iv) a fixed number of presented objects at any giventime; (v) a variable number of presented objects at any given time; (vi)presented objects have the same characteristics; (vii) presented objectshave different characteristics; (viii) duration of visibility of eachpresented object is the same; (ix) duration of visibility of eachpresented object is different; wherein data indicating an effect or noeffect of a characteristic of a presented object on the subject'sbehaviour with respect to a presented object provide information aboutbrain injury and/or a neurological disorder in the subject.
 13. Themethod of claim 1, further comprising: changing one or morecharacteristics of the environment in which objects are presented to thesubject, including: (i) presenting distracter objects, which the subjectis instructed not to interact with; (ii) presenting barriers, real orvirtual, that the subject must move around while attempting to interactor not interact with the objects; (iii) presenting workspace-definedforce-fields, such as gravity wells; (iv) presenting audio to thesubject; wherein data indicating an effect or no effect of acharacteristic of the environment on the subject's behaviour withrespect to a presented object provide information about brain injuryand/or a neurological disorder in the subject.
 14. The method of claim1, further comprising: changing one or more characteristics of thesubject's interface in the environment, the one or more characteristicsselected from: (i) providing body-defined force-fields, as a resistance,force, or bias to the subject's limbs; (ii) modulating spatial and/ortemporal alignment of the presented objects relative to the subject'slimb movement; (iii) modulating at least one property of arepresentation of the subject's limbs used to hit or interact with theobjects in the environment, wherein the modulated property is selectedfrom width, length, shape, and a combination thereof; and (iv) providinga representation of the subject's limb geometry.
 15. The method of claim1, further comprising: obtaining gaze position data as the subjectinteracts with the objects; wherein gaze position data together with theacquired data set provide information about brain injury and/or aneurological disorder in the subject.
 16. The method of claim 1, whereinanalyzing comprises comparing the data set with control data. 17.Apparatus for diagnosing, assessing, or detecting brain injury and/or aneurological disorder of a subject, comprising: a display device thatpresents objects to the subject within the subject's workspace such thatthe subject can choose to interact with the presented objects usingeither the right or left limb, or portion thereof, of a pair of limbs,wherein the display device displays a representation of the subject'slimbs or portions thereof; data acquisition apparatus that obtainsposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object; andcomputer readable media that directs a computer to perform one or moreof: present the objects on the display device such two or more objectsare in the subject's workspace simultaneously; or such that a nextobject is presented to the subject before the subject can move the rightor left limb, or portion thereof, to a selected position afterinteracting with a previous object; present the representation of thesubjects limbs or portions thereof on the display device; input andanalyze the position data and/or motion data and/or kinetic datacorresponding to the subject's left limb and right limb with respect tothe presented objects; including determining from the position dataand/or motion data and/or kinetic data whether the left limb or rightlimb was used with respect to a presented object, and repeating thedetermining for a plurality of presented objects; output informationabout condition of the brain and/or neurological status in the subject.18. The apparatus of claim 17, wherein the data acquisition apparatusthat obtains position data and/or motion data and/or kinetic data of thelimbs comprises a mechanical linkage adapted to be attached to eachlimb.
 19. The apparatus of claim 17, wherein the data acquisitionapparatus that obtains position data and/or motion data and/or kineticdata of the limbs comprises a mechanical linkage adapted to be graspedby the subject.
 20. The apparatus of claim 17, wherein the dataacquisition apparatus that obtains position data and/or motion dataand/or kinetic data of the limbs comprises one or more sensors adaptedto be attached to each limb, and a detector that detects output signalsfrom the one or more sensors, or one or more cameras.
 21. A method forobtaining position data and/or motion data and/or kinetic data of theleft and right limbs or portions thereof of a subject, comprising:presenting objects to the subject within the subject's workspace suchthat the subject can choose to interact with the presented objects usingeither the right or left limb, or portion thereof, of a pair of limbs;using data acquisition apparatus to obtain position data and/or motiondata and/or kinetic data of the left and right limbs or portions thereofwith respect to a presented object; constructing a data set from theobtained data for a plurality of presented objects; and analyzing thedata set and outputting a result that provides information aboutcondition of the brain and/or neurological status in the subject;wherein analyzing comprises determining from the position data and/ormotion data and/or kinetic data whether the left limb or right limb wasused with respect to a presented object, and repeating the determiningfor a plurality of presented objects to produce the acquired data set;wherein presenting objects includes presenting objects to the subjectwithin the subject's workspace such that two or more objects are in thesubject's workspace simultaneously; or wherein a next object ispresented to the subject before the subject can move the right or leftlimb, or portion thereof, to a selected position after interacting witha previous object.
 22. The method of claim 21, further comprising usingthe result to diagnose, assess, or detect brain injury and/or aneurological disorder in the subject.
 23. A method of diagnosing,assessing, or detecting brain injury and/or a neurological disorder of asubject, comprising: analyzing a data set to determine a brain injuryand/or a neurological disorder of a subject; wherein the data set isobtained by: presenting objects to the subject within the subject'sworkspace such that the subject can choose to interact with thepresented objects using either the right or left limb, or portionthereof, of a pair of limbs; using data acquisition apparatus to obtainposition data and/or motion data and/or kinetic data of the left andright limbs or portions thereof with respect to a presented object;constructing the data set from the obtained data for a plurality ofpresented objects; wherein presenting objects includes presentingobjects to the subject within the subject's workspace such that two ormore objects are in the subject's workspace simultaneously; or wherein anext object is presented to the subject before the subject can move theright or left limb, or portion thereof, to a selected position afterinteracting with a previous object; or wherein the data set is obtainedby: presenting objects to the subject within the subject's workspacesuch that the subject can choose to interact with the presented objectsusing either the right or left limb, or portion thereof, of a pair oflimbs; presenting one or more distractions to the subject while thesubject is interacting with a presented object; using data acquisitionapparatus to obtain position data and/or motion data and/or kinetic dataof the left and right limbs or portions thereof with respect to apresented object; and constructing the data set by obtaining positiondata and/or motion data and/or kinetic data of the left and right limbsor portions thereof for a plurality of presented objects; whereinanalyzing comprises determining from the position data and/or motiondata and/or kinetic data whether the left limb or right limb was usedwith respect to a presented object, and repeating the determining for aplurality of presented objects; and outputting a result that providesinformation about condition of the brain and/or neurological status inthe subject.